As with most - this as happened to us at some point in time. For me it was always gradual - except for those times when I was fine - but the other person wanted a change, then it's fairly abrupt.

Once I had come to the conclusion that it was time to move on - then things went pretty fast. If necessary I lined up the necessary alternate living arrangements, made the move - and didn't look back.

My tendency is to let things cool down for a while - in fact once I didn't date for 1 year to clear my head.

You have to do what's right for your situation. I'm sorry to hear that you are having these issues - but in the end you may find that it leads you to a new love - a permanent love built of respect, compatibility and passion.

--Do you fall out of it fast and need an immediate break?
--Is it slow and gradual, sneaking up on you in time?
--How do you deal with it?
--Do you still try to work it out or are you just over it?

For me it was slow, it just kept coming up, each time a little firmer in my head. Then one day it hit me what it was.
I asked myself why I was unhappy. If I would be happier by myself.
The "work on question"
Well, it would depend on what was to "work on" most of the time there was nothing to "work" on and I just cut my losses.
But you can fall out and back in love with someone it jsut depends. If its that "spark" you are talking about you can get it back or at;east I have been able to . But It takes a lot of work on both ends and you have to aske yourslef if thats somting you want and if its worth it. Or you can cut your losses. For me most of the time I cut my losses.

--Do you fall out of it fast and need an immediate break?--Is it slow and gradual, sneaking up on you in time?--How do you deal with it?--Do you still try to work it out or are you just over it?

It's definitely a slow process, and in retrospect it seems blatantly obvious what was going to happen. I'm the type of person that always tries to work it out, but sometimes the resentment or indifference just makes it too hard. When I know something is not salvageable, I just walk away and never turn back.